Center-finder.



D. L. SAUERHERING.

CENTER FINDER.

APPLICATION FILED APR. 2, 1915.

Patented June 20, 1916.

BY W

A TTOR/VEYS CENTER-FINDER.

Specification of Letters Patent.

Patented dune 2d, lldtfi.

Application filed Apri12, 1915. Serial Ito. 18,711.

by one hand for quickly and exactly determining the center of square, round, elliptical, octagonal, hexagonal, or other shafts of regular cross sectional configuration.

Another object of the invention is to provide an improved, center finder provided with adjustable radially extending arms universally connected and adapted to be grasped by the fingers of one hand for centering the device, a punch being provided capable of being struck by an instrument carried in the opposite hand of the operator for marking the center.

A further object is to provide such a device as I have described, having its arms calipered whereby the exact diameterof the shaft being marked or centered may be ascertained at the same time that the center of the shaft is being found.

With-these and other objects in view which will become apparent as the description proceeds, the invention resides in the construction, combination, and arrangement of parts hereinafter more fully described and claimed, and illustrated in the accompanying drawing in which like characters of reference indicate like parts throughout the several figures of which- 1 Figure 1 represents a plan view ofacenter finder constructed according to my invention, showing the same in operation. Fig. 2 represents a plan view of the same, enlarged, the top or upper plates having been removed. Fig. 3 represents a view in section taken transversely on the plane indicated by the line 3-3 of Fig. 2. Fig. t

represents an inside plan view of one of the plates. Fig. 5 represents a view in section of the outer end of one of the arms or bars.

In carrying out my invention, I provide an upper plate and a lower plate 5 and 6 respectively, which when in assembled positlon are disposed at right angles to each other, with respect to the channels in them provided, as hereinafter described. The plates are each made exactly alike, and as incated in Fig. 4 are provided each with a pair of spaced parallel channels 7 in which a pair of the arms or rack bars 8 are adapted to slidably extend.- Each plate is provided with a central opening at 9 for the reception of one end of a central shaft 10. Around the opening 9 and intermediate the channels and is in a plane with the fioor of the chan-;

nels 7. The arms 8 are preferably four in number, and are disposed in pairs at right angles to each other, the members of each pair being in parallel and in spaced relation with each other.. Each of the arms is.

adapted to be slidably disposed in one of the channels '7. The arms are toothed on their inner edges as at 12, and at their outer ends are bent at right angles as at 13 and then turned downwardly as at 14:, to form sub stantially triangular shaped jaws disposed in a plane" at right angles to the plane of the arms.

When in assembled position a pair of the arms is supported in. the lower plate 6, and

another pair in the upper plate 5, the latter pair being disposed above the lower pair and adapted to move in lines at right angles to the line of movement of the lower pair.

, The shaft or stem 10 is provided with a central bore 1 enlarged ht its upper end as at 4, and having a shoulder 3 formed at the junction of the enlarged portion'with the reto 'slidably receive the shank of a unch 14 having a sharpened lower end 15 an proat maind'er of the bore. The bore 1 is adapted tion of the flared collar 16 when the punch a is in normal position. Surrounding the shank 14 and interposed between collar 16 and floor or shoulder 3 is a coiled spring 29 whose normal tendency is to maintain the punch in outward position, that is wlth the 'point flush with or above the lower surface ofthe under plate 6. Formed integrally on the shaft 10 beween the ends thereof is a pinion wheel 19 of a thickness substantially equal to the thickness of two of q the arms 8, and equal to the depth of the recess formed by the combined rabbets 11 in the two plates. This pinion is adapted to rotate within the recess thus formed surrounding the openings 9. When in assembled position, each of the arms or rack bars 8 is in mesh with the pinion 19.

The plates are provided with a pair of alined openings 20, for the reception of screws or other securing elements 21, the openings in the lower plate 6 being preferably threaded for the reception of sald screws, while the openings, in the upper plate 5 are preferably smooth bored.

The inner ends of arms 8, or those ends opposite the jaws, are provided with upwardly extending lugs 22 adapted when the arms are shifted to the extremity of their outward movements to engage against the plates whereby to limit the outward move ment of the arms and prevent loss of said arms from the device. The upper surfaces of arms 8 are graduated or calipered as at 23, in order that the diameter of any shaft which is being centered, may readily be ascertained by simply glancing at the graduated surfaces.

In operation the arms are shifted outwardly and the device is then placed in one hand on the shaft end and the fingers are utilized in grasping the jaws and moving them into engagement with the shaft, until said jaws lie in engagement with the outer surface of the shaft, and a suitable instrument such as a hammer or sledge is then utilized in striking the upper protruding end of the punch 14, hence shifting the punch against the tension. of the spring 20, and making an indentation in the center of the shaft end. The spring instantly operates to 4 retract the punch from the shaft and into its normal position. At the same time that the shaft is being centered, the dimensions of the shaft with regard to its cross sectional area may be readily determined by reading the graduations on the arms.

Such a device as I'have provided is extremely simple, and provides few parts not likely to readily become out of order. Should the punch require repairing the bushing 17 may be readily removed and the punch lifted out, either to be sharpened or repaired or replaced by a new one.

The pinion 19 it will be noted is not utilized ininitially shifting the arms for centering the device, but is merely used for imparting uniform motion to the arms, the adjustment of said arms being obtained as heretofore set out by the fingers of the operator.

Although I have described the preferred embodiment of my invention, I may desire to make such changes in the construction, combination, and arrangement of parts thereof, as do not depart from the spirit of the invention and the scope of the appended claims.

I claim 1. A center finder comprising a pair of plates secured together face to face and being each provided on its inner face with a pair of spaced parallel channels, the channels in one plate extending at right angles to the channels in the other, an arm slidably disposed in each channel and having its inner edge toothed, said arm being of a thickness and width substantially equal to the depth and width respectively of the channel, said plates being provided centrally with alined openings, a shaft rotatably extending through the openings and being provided with a pinion adapted to rotate in a recess provided in the inner faces of the plates and being in mesh with the teeth on the said arm, said shaft being provided with a central bore having an enlarged portion at one end, a shoulder formed at the inner terminal of the enlarged portion, a punch having its shank slidably extending through said bore and having a collar extending within the enlarged portion of the bore, a coiled spring interposed on the shank between the collar and shoulder and normally tending to maintain the unch in such position that its point is hel within the bore, a bushing surrounding the shank above the collar and being threaded into the outer end of the enlarged portion, jaws formed on the outer ends of the arms and extendin at right angles to the plane of said arms, ugs formed on the inner ends of the arms and adapted to limit their outward movements, and graduations provided on the outer surfaces of the arms.

2. A center finder comprising a pair of plates secured together, arms arranged in spaced relation to each other between the plates for sliding movement, a shaft r0- tatably extending through alined openings in the plates and provided with a wheel engaging the arms for operating them said shaft provided with a central bore having mamas m an enlarged portion at one end, a shoulder and a bushing threaded into the outer end. formed at the inner terminal of the enlarged of the enlarged portion and through which 10 portioin, a punch haxiling its Shfilk slidably the shank slidably extends. exten ing through t e bore an having a 5 collar arranged in the enlarged portion of DOUGLAS SAUERHERING' the bore, a spring arranged between the Witnesses: collar and shoulder tending to retain the H. A. BEILKE, punch with its point housed Within the bore, T. M. LAURIsoH. 

